I'm not saying that all cops are racial bigots. We all know that they're not. But we also know that some of them are. And the drug war permits them to exercise their racial bigotry to their heart's content — and even get praised and thanked for their service while doing so.
After all, let's face it: there are racial bigots in society, and there will always be racial bigots in society. Anyone who thinks he is going to wipe out racial bigotry through "education" and "enlightenment" is living in la la land.
When someone engages in racial bigotry on a private level, he is subject to private and peaceful retaliatory measures, such as loss of sales if he is a business owner or the loss of a job if he is an employee. He is also subject to criticism and social ostracism. The free society makes the bigot bear an economic and social penalty for his bigotry, which might well nudge, not force, him into better behavior.
It's totally different with drug laws. They have converted police departments into magnets for racial bigots. With the drug war, cops are empowered to stop blacks arbitrarily and subject them to abusive interrogations and intrusive, demeaning, and oftentimes violent searches and seizures of their persons, automobiles, and homes.